usbcore: non-hub-specific uses of autosuspend

This patch (as741) makes the non-hub parts of usbcore actually use the
autosuspend facilities added by an earlier patch.

	Devices opened through usbfs are autoresumed and then
	autosuspended upon close.

	Likewise for usb-skeleton.

	Devices are autoresumed for usb_set_configuration.


Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 9b542a6..1b51d31 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -90,6 +90,11 @@
 		goto exit;
 	}
 
+	/* prevent the device from being autosuspended */
+	retval = usb_autopm_get_interface(interface);
+	if (retval)
+		goto exit;
+
 	/* increment our usage count for the device */
 	kref_get(&dev->kref);
 
@@ -108,6 +113,12 @@
 	if (dev == NULL)
 		return -ENODEV;
 
+	/* allow the device to be autosuspended */
+	mutex_lock(&dev->io_mutex);
+	if (dev->interface)
+		usb_autopm_put_interface(dev->interface);
+	mutex_unlock(&dev->io_mutex);
+
 	/* decrement the count on our device */
 	kref_put(&dev->kref, skel_delete);
 	return 0;